A towering header from a Matt Jarvis cross brought the Croat his goal in a hard-working display and Petric insists he is improving with every passing day.
He told West Ham TV: "It was a good day, I played 90 minutes after a long time which was very good for me and of course I'm glad to score a goal but it's only a friendly, so it doesn't count for too much.
"It was good, not just for my fitness, but some other players as well and it was very important to get 90 minutes. I feel better and better each day and I don't think it's long before I will feel 100 per cent fit."
Petric added: "It's been nice, they're all very kind, very good lads and every day I've been enjoying it. I get on well with everybody, of course I get on well with Guy [Demel], because I know him from Hamburg and Raphael Spiegel, because he's from Switzerland and we speak the same language. "
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